Recent advances in our understanding of the physiology, biochemistry and molecular biology of the arthropods that transmit agents of disease have been gratifying, such that a body of information detailing the contact between vector and host has begun to emerge. Particularly interesting are responses stimulated by contact host. These include vitellogenesis, oogenesis, pheromone production, digestion, salivation, mating, sperm activation and development of pathogens. Such diverse arthropods as mosquitoes and ticks, tsetse flies and bugs, sandflies and fleas and vectors of plant as well as animal infections have been the subjects of these studies. The similarity of the stimuli that initiate these processes provides the focus of the proposed symposium. We anticipate that basic concepts relating to disease transmission will arise from this attempt to describe how vector arthropods respond to their hosts. The proposed symposium is a continuation of the 1986 and 1989 Vero Beach Symposia and are designed to further promote communication between the scientists addressing this range of topics. Sufficient time for extensive communication will be provided by the extended format and the unitary focus of discussion. Support is thus requested for a 4-day international symposium entitled "Host Regulated Developmental Mechanisms in Vector Arthropods" that will convene in February 1993, and for assistance in publishing a symposium proceedings.